Dont you wish all this stuff was condensed? I never would have found that.
Yeah, like a "Common Problems FAQ" for 'tards like me! Of course, it would take someone with the deep knowledge to write it. And there are many here who I've already learned so much from. 'Saved me $100s in amp tech visits. Thank You All and you know who you are!
I searched "Bad Distortion" "Weird Distortion" "ZZzztt" (with many combinations of "Z" and "t") "Farting" etc. Then you have to follow links within those answers. A crash course in speed reading, and a mountainous curve for a first time builder. Worth every minute.
I layed into the amp last night for an hour and a half, and The Sound came back. SHzzITT!
I kept on playing 'cause besides that small annoyance, everything else is there in spades.
Back on the bench later tonight, I'll post all readings. I know the bias hasn't drifted much on the JJs, as I check everytime I take a break, just to see. I might move the purple wire to the 8 ohm tap (on the 16 ohm tap right now). The Presence purple wire has plenty of air and distance from the tone controls. It's a tad shuffly sounding when rolling, but no squeal.
Also going to re-check under board for OT wire routing, twisting, and clearances. Temp undo zipties like Junkie said and move stuff around. The OT puts out the most hum with the Standby switch on. Gonna make sure ground wires lay on the chassis and the OT wires float over them.
I had a vision (don't laugh) that something might be amiss in the "push-pull" part of the operation, causing the amp to give it up, or cave in momentarily (ok, now you can laugh). What does that mean? Don't ask me.
Got any of that Crown Royal left? I need one. Somebody Get Me a Doctor!